I would say he needs professional if not psychological help. I don't think there is anything you can do other than support him and encourage him to get help. It sounds like it is in his head, not his body and he never learned how to know when he was full because all of his meals were scheduled and prepared for him. He ate when he was told to eat, but college is different. Junk food can give quick bursts of energy, but will leave him feeling more tired over all during a time when he is supposed to feel tired. . . . because all college students feel tired.